Separation steering algorithm for separationg set of Rectangles

While trying to figure out how solve this problem I read some questions and look their source code. I find that they not only move room after every overlapped neighbour found but also move neighbour in other direction!

What about directional behaviour of separation? It's my mistake or misunderstanding of rounding to integer

What about perfomance? Generating 512 rooms inside circle with radius of 128 units using normal distribution give 1100 ms

Now, code looks like:

private void SeparateRooms()
        {
            do
            {
                for (int current = 0; current < rooms.Count; current++)
                {
                    for (int other = 0; other < rooms.Count; other++)
                    {
                        if (current == other || !rooms[current].IsOverlapping(rooms[other])) continue;

                        var direction = (rooms[other].Middle - rooms[current].Middle).normalized;

                        rooms[current].Move(-direction, TILE_SIZE);
                        rooms[other].Move(direction, TILE_SIZE);
                    }
                }
            }
            while (IsAnyRoomOverlapped());

            StopTimer(true);
        }

And Room's Move() method:

public void Move(Vector2 move,int tileSize=1)
        {
            x += Mathf.RoundToInt(move.x)*tileSize;
            y += Mathf.RoundToInt(move.y)*tileSize;
        }